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Ganges Basin Development Challenge
Objective: Improve resource productivity and increase the resilience of agriculture and aquaculture systems of brackish coastal areas of the Ganges
G4: Assessment of the Impact of Anticipated External Drivers of Change
on Water Resources of Coastal Zone
Ganges Basin:
Ganges Basin Area = 1,087,300 sq. km
Study Area:
Ganges Dependent Area in Bangladesh
Coastal Divisions: Barisal: Patuakhali, Barguna, Jhalakati & Pirojpur districtsKhulna: Khulna & Satkhira districts
Project Target Area:Coastal Zone of the Ganges basin in Bangladesh except the Sundarbans
Problems and Challenges in the Coastal Region of Bangladesh
Water logging
Increase in precipitation in monsoon
Decrease in precipitation in dry season
Salinity intrusion
Cyclone
Sea level rise
Increased frequency of tropical cyclone
Added siltation on the drainage route
Salinity intrusion
Flood
Salinity Intrusion
Important Developments: •Coastal Zone Policy•Coastal Development Strategy•Priority investment program•Community capacity to enhance livelihoods•Enabling institutional environment•Integrated knowledge base
Water Related Issues: •Water, land and ecosystem management •Community participation in water management•Equitable allocation of multi-purpose cyclone shelters•Rationalization of coastal polders• Restoration of inflow to the Ganges distributary by basin wide management•Salinity intrusion•Drainage congestions & Sedimentation•Climate change and climate variability
DRIVERS PRESSURE/CONSEQUENCESDemographic/SocietalPopulation growth, Land use change
Water demand & useLoss of biodiversity and wetlands
Economic/TradeEconomic develpopment (change in per capiata income)Market value of agricultural products
Shift in land useWater Demand, water PollutionRoads, railway & ports
Political/Institutional/LegalWater policy (national and regional)
Improved Irrigation and drainage system, Water availability in the dry season
Environmental/Climate ChangeSea level rise due to Climate ChangeChanges in precipitation and temperature due to Climate Change , Subsidence
Fresh water shortage, Salinity intrusion, FloodSedimentationMore Cyclone & Storm surge
Technological/Important Innovations aquaculture and agriculture intensification, Water infrastructure development
Enhanced knowledge and use of HYVEnabling environment
Drivers of Change: Participatory Approach
Place: Fultola, BatiaghataParticipant: Farmers (3 women, 20 men)
Priority Issue1 Increase of water level & salinity intrusion, Polder needs to be raised, some of the
existing gates need to be repaired and new gates are required to be constructed
2 Need improvement in drainage and excavation of new drains/canals, new sluice gates/inlet-outlet
3 WGMs want to be able to operate the gates themselves and to lease the ‘Khas lands’ near the embankment and gates to generate funds for their activities.
4 Stop leasing of the canals
5 Solve the problem of river siltation and improve navigation
6 Water management through public representation and partnership
7 Capacity building and training
Community Consultation at Polder 30
Place: Kismat-fultola, BatiaghataParticipant: Fishermen (6 women, 9 men)
Priority Issue
1 Stop leasing the canals
2 Stop placing ‘net’, ‘pata’, ‘charu’ or obstruction in the canals/river
3 Increase depth and flow in canals
4 Stop catching mother fish carrying eggs
5 Reduce using pesticides for agriculture
6 Stop unnecessary catching of juvenile fish of other species
7 Stop complete drying of canals while irrigation so that some fish/egg may survive/remain in the canals for future growth
Popu
latio
n G
rowt
h
Chan
ges
in W
ater
Mgt
Sea
leve
l rise
Land
use
cha
nge
Wat
er S
harin
g
Tran
sbou
ndar
y flo
w
Aqua
cultu
re in
tens
ifica
tion
Econ
omic
Deve
lpop
men
t
Urba
niza
tion
Wat
er in
frast
ruct
ure
deve
lop.
..
Chan
ges
in p
recip
itatio
n
Wat
er P
olicy
Indu
stria
lizat
ion
Wat
er G
over
nanc
e &
Inst
itut..
.
Wat
er U
se c
hang
e
Mar
ket V
alue
of A
gro
Prod
ucts
Chan
ges
in te
mpe
ratu
re
Diet
ary
patte
rns
Wat
er P
ricin
g &
Insu
ranc
e
6.5%6.1%5.9%
5.7%5.7%5.5%5.4%5.4%5.4%5.4%
5.2%4.8%
4.6%4.6%4.4%4.3%4.2%
3.2%2.8%
Perc
enta
gePreliminary Results of Questionnaire Survey
Hydrologic Trend Analysis in the Study Area:
1930 1940 1950 1960 1970 1980 1990 2000 20100
10000
20000
30000
40000
50000
60000
70000
80000
90000Hardinge Bridge on the Ganges
Max Q Linear (Max Q) Min Q Linear (Min Q)Average Q Linear (Average Q)
Disc
harg
e (m
3/s)
• Increasing trend of annual maximum flow
• Decreasing trend of annual minimum flow
Trend Analysis of Ganges River Discharge
Hydrologic Variables:Trend Analysis in the Study Area:
Trend Analysis of Water Level
1980 1985 1990 1995 2000 2005 2010-2
-1
0
1
2
3
4 Hiron Pointon the Pussur River
Max of WL Linear (Max of WL) Min of WLLinear (Min of WL) Average of WL Linear (Average of WL)
Wat
er L
evel
(mPW
D)
• Rising trend of water level near the sea
1999 2001 2003 2005 2007 20090
1
2
3
4Hiron Pointon the Pussur River
Max of WL Linear (Max of WL)
Wat
er L
evel
(mPW
D)
The increase of maximum water level is 6 cm/yr at Hiron Point in the last 10 years.
Jan/
2005
Jan/
2005
Mar
/200
5Ap
r/20
05M
ay/2
005
May
/200
5Ju
n/20
05Ju
l/20
05Au
g/20
05Se
p/20
05O
ct/2
005
Nov
/200
5De
c/20
05Ja
n/20
06Fe
b/20
06M
ar/2
006
Apr/
2006
May
/200
6Ju
n/20
06Ju
l/20
06Au
g/20
06Se
p/20
06O
ct/2
006
Nov
/200
6De
c/20
06Ja
n/20
07Fe
b/20
07M
ar/2
007
Apr/
2007
May
/200
7Ju
n/20
07Ju
l/20
07Au
g/20
07Se
p/20
07O
ct/2
007
Nov
/200
7De
c/20
07Ja
n/20
08Fe
b/20
08M
ar/2
008
Apr/
2008
May
/200
8Ju
n/20
08Ju
l/20
08Au
g/20
08Se
p/20
08O
ct/2
008
Nov
/200
8De
c/20
08Ja
n/20
09Fe
b/20
09M
ar/2
009
Apr/
2009
May
/200
9Ju
n/20
09Ju
l/20
09Au
g/20
09Se
p/20
09O
ct/2
009
0
2
4
6
8
10
12
Noapara Ghat Fultola Ghat Charerhat Ghat Rupsha Ghat Mollarhat
Salin
ity (P
PT)
Salinity Trend in the Region
Monthly Salinity Monitoring (Data Source: Department of Environment, DOE)
Population growth• One of the densely
populated country
• Projected population
o 2025: 180million
o 2050: 220 million
• Urban: 25 million (2001), 80 million (2025) & 140 million (2050)
• Reduction of agricultural land 1% annually
70
80
90
100
110
120
130
140
Po
pu
lati
on
(m
illio
n)
7.0
7.5
8.0
8.5
9.0
Cro
pp
ed
are
a (
millio
n h
a)
Cropped areaPopulation growth
020406080
100120140
1998
2005
2015
2025
2035
2045
Rural Urban
Coastal Polders in Bangladesh
In the early sixties and seventies, 125 polders (of which 49 are sea-facing) were constructed to protect low lying coastal areas from tidal flood & salinity intrusion.
West Bengal Bangladesh
Polder 43/2/F trials
Polder 30 trials andstudy watershed
Polder 3 trials
S elected Polder in coastal zone of Bangladesh and West Bengal
Trial sitesG1 IRRI – IWM – LGED - SRDI
0 SLR60 cm SLR120 cm SLR
Impact of SLR on Intrusion of 5ppt Salinity line Dry Season
Hiron Point
95 km
55 km
Sundarbans
Khulna
Barisal
Bhal
esw
ar R
iver
Tent
ulia
Riv
er
BholaBarguna
Patuakhali
Sea Level Rise (SLR)
Affected area (ha)due to SLR
Affected Population due to SLR
60cm 512,590 4,613,306120cm 1,061,016 9,549,144